Chapter 9 Fire Pumps Theory Flashcards
Except for a few well developed municipal water sytems, it is necessary to _________ the existing pressure to with fire dept pumpers to maintain pressure sufficient for fire fighting ops
increase
Static water supply includes ___,____ and ______
tanks, ponds or lakes
Early pumps in Fire service were hand operated ___________ pumps
piston
After piston pumps came _______ pumps using a hand crank to rotate a gear.
rotary
Rotary pumps were replaced by _______ and ______ action piston pumps of various diameters and strokes. These pumps are referred to as __________ displacement pumps
single and double
positive
Positive Displacement pumps are _________ priming, deliver and _____ volume of water or air, and and exhaust air from the pump and deliver ______
self
definite
water
Positive Displacement Pumps are “_________________” in that they produce the same flow at a given speed regardless of discharge pressure.
“Constant Flow Machines”
Modern fire Apps continue to have a form of positive displacement pump called a __________ that is connected to main pump to allow App to use static water supplies.
priming pump
Positive Displacement pumps are used for ___________, and priming pumps
hydraulic pumps on aerial devices
Modern fire Apps MAIN pumps are __________ pumps
centrifigal
Centrifigal pumps rely on the ________ of water to create centrifigal force
velocity
A _______ pump is a positive displacement pump that uses one or more reciprocating pistons to force water from the pump chamber
Piston
Piston pumps are no longer used as high capicity pumps, some are still in service for ______ pressure streams. These multi cylinder PTO driven pumps can provide pressures of ________psi
high
1,000 psi
Rotary pump is a ______ capacity pump used for ______ type pumps
small
booster
Rotary pumps are: ____, _____ and _____ pumps
low volume, high pressure and priming
Rotary type pumps are either:
1.
2.
rotary gear or rotary vein
Rotary pumps are driven by either:
1.
2.
small electric motor
clutch off drive shaft
the ____ gears on a rotary pump contact each other and the casing forming ______ and _______ tight pockets
two
air and water
The ammount of water that can be pumped by a rotary gear pump depends on the size of the ______ in the gears and the _______ of rotation
pockets
speed
If a positive displacement pump tries to move more water than the discharge line can handle, ______ builds
pressure
a _______ valve must be in place to handle excess pressure on a positive displacement pump
Positive displacment pumps are susceptable to dmage from normal _____ and ______ and pumping water laden with _______ and other debris.
ware and tear
sand
Most positive displacement pumps feature gears made of ____ or other soft metals and casing made of ________
bronze
cast iron
Rotary Vane Pumps: Has moveable elements that automatically _____ for wear.
compensate
___________ are the most common types of pumps used to prime centrifigal pumps
rotary vein pumps
on a rotary vein pump, the distance between the rotor and the housing are much ______ at the intake than at the discharge
greater
As the rotor turns, the veins are ______ against the housing by centrifigal force
forced
the veins in a rotary vein pump are worn, they _____ further and make contact making them better than rotary gear pumps at moving ______
slide
air
Rotary pump are prone to _____ if not excercised regularily. The should be operated during routine _____ checks
failure
apparatus
Nearly ALL modern Fire Apps feature a _______ pump as the main pump.
centrifigal
Centrifigal pumps are classified as __________ diplacement pumps
non positive
A centrifigal pump works by throwing water from the center to the ______ of the disk
outer edges
The faster a disk is turning on a centrifigal pump the more ______ is created
velocity
_______ is a spiral divergent CHAMBER of a centrifigal pump in which the velocity energy by impeller is converted to ________
Volute
pressure
In the volute increasing size reduces the ______ of water inabling the ________ to build up
velocity
pressure
discharge volume on a centrifigal pump affects both the ______ and ______ pressures
intake and discharge
Increasing speed is roughly equal to the ______ of the change in impeller speed.
doubling impeller speed means _____ times the water
square
4
any movement of the impeller increases both ______ and ________ buildup of water in the volute.
velocity and corresponding pressure.
Three ways to prime a centrifugal pump include rotary vein and a device the uses the braking system to power a ______ device that removes air. And finally a ______ valve on the suction hose ________
venturi
foot valve
strainer
two types of centrifugal pumps. _______ stage and ______ staged
single
multi
Single stage centrifugal pumps generally have flow capacities of up to _________ gpm
2,250
Newtons third law of physics is that for every…….
action there is an equal and opposite reaction
A double suction impeller takes water from ________ sides. the reaction of each side being equal and opposite cancels out the _______ thrust
both
lateral
_______ edges in the opposite opposed volute discharge and divert the water into _____ streams that are ____degrees apart. this reduces stress and prolongs life of App and pump.
Stripping edges
two
180 degrees
The ________ valve changes multistage pumps from volume to ________
transfer
pressure
pumping in parallel is ________ mode
volume
pumping in series is ____ mode
pressure
in volume mode each impeller is capable of flowing ____ % of it’s rated capacity
50%
If a pump is rated for 1000gpm at 150 psi and you are pumping in volume. each impeller is pumping _____gpm for a total discharge pressure of ______psi. Note that intake pressure will ______increase this number.
500gpm
150psi
In series/pressure mode, the first impeller increases pressure _____to_____% of the volume capacity through the transfer valve
50-70%
The process of switching to volume or pressure mode is sometimes called “_____”
changeover
When a transfer valve is operated sudden changes in _____ can occur. switching to volume to pressure can _______ pressure
pressure
double
Any changeover from volume to pressure or vice versa must be carefully coordinated with attack crews so they will be _____ for a slight interuption during the transfer.
ready
If you there is question as to the correct position for the transfer valve, it is best to opperate in _______
parallel(volume) mode
In parallel the pump is capable of supplying _____% of it’s rated capacity at ____psi at ____feet of lift with _____feet of suction hose
100 %
150 psi
10 feet lift
20 feet suction hose
Many power operated transfer valves operate at pressures as high as _____psi
200 psi
power operated transfer valves may be activated by electricity, _____ pressure or ______pressure. D/O must be familiar with the ______ override features should the power equipment fail
air pressure
water pressure
manual override
Transfer valves have a safeguard making it physically impossible to accomplish transfer while pumping at ________
high pressure
Some fire trucks have been constructed with ___ impellers connected in series to develop pressures as high as ________ for high pressure fog operations
4
1,000gpm
Another method to increase pressure is a single stage used with a _____ stage pump. When pressure higher than _____psi is needed the seperate third stage pump is engaged. These pumps are usually for high rise buildings
two
250 psi
The distance between the pump casing and the hub is usually limited to _____inches
.01 inches.
A pump reaches it’s capacity at around ________RPM
4,000
_______ are attached to the impeller and pump casing to allow a small clearance to prevent wear
wear rings
It is ok to shut discharge valves with a centrifugal pump is running. It will only start to _____ the water. Positive displacement pumps CANNOT have discharge shut while running.
heat
Newer centrifugal pumps may have a ______ relief valve to assit when pump is overheating from no recirculation of water.
thermal
The D/O can place a hand on the direct pump intake valve to check for ___
heat
At the point where the shaft passes through the pump casing, a semi-tight seal must be maintained to prevent ______. _________ seals are the most common type to prevent this
air leaks
mechanical
The most common type of seal packing is composed of ______ impregnated with _____ or ______
rope fibers
graphite or lead
seal packing is pushed into a stuffing box by a packing gland driven by a ___________
packing adjustment mechanism
Some centrifugal pumps are equipped with ______ or mechanical seals
ceramic
Packing rings are primarily used in ________fire pumps
older
In order to overcome heating where th packing ring rubs the shaft, spacers known as ______ or_______ is supplied with the packing to provide cooling
lantern or slinger ring
if packing rings are too loose and water leaks it might not be possible to ______ with the pump because it is not air tight.
draft
If pump s not used for extended periods of time, the packing may ________ causing excessive leaking
dry out
After a period of dryness to packing, adjustments to packing should be made after pump has been operated under pressure so packing can seal properly
no answer
If a pump is operated dry, damage to the ______ can occur
shaft
ceramic pumps seals are superior in that they resist to ______, ______ and corrosion.
warping, stretching
When considering buying a pump, consider:
1. use of pump
2.
3.appearance
4. space requirements
5.
cost
ease of maintenence
Pumps powered by gas or deisel engines INDEPENDENT of the vehicle-drive engine are examples of _________ pumps
auxiliary
Most common applications for auxiliary pumps are:
1.
2.
3.
4.
5.
- ARFF
- Wildland apps
- mobile water supply apps
- trailer mounted apps
- Portable fire pumps
Some auxiliary pumps are powered by ____ fuel for military or other special applications.
Some auxiliary pumps are mounted on a pickup with a capacity of _____gpm
500 gpm
PTO is a mechanism that allows an engine to power equipment such as a _____, ______ or _______ tool.
pump, winch or portable tool. it is attached to the transmission.
PTO pumps are most common on these applications:
1.
2.
3.
- intitial attack
- wildland
- mobile water supply applications
PTOs are even being widely used on __________ apparatus pumpers
structural
Rear engine PTOs are driven off the engines ________. these have had sucess in construction and refuse industries
flywheel
PTO offers pump and roll capabilities as well as a _________ wheel base and _______ room in compartments as well as ______lays that are lower on app
shorter
additional
crosslays
Pump gear case must be mounted in a location that allows for a ________ of angles in the drive shaft
minimum
The PTO is powered by an _______ in the vehicles transmission.
when a D/O _______ the clutch to stop or change gears, the pump also stops turning.
disengages
PTO allows ump and roll but it is not as effective as a ______ engine unit
seperate
Pump and roll. pressure in pump changes as D/O increases driving ______
speed
If using pump and roll, a ______ guage should be mounted in the cab.
pressure
While hoselines are in use during pump and roll, use the ______ guage and not speed of vehicle as a guide.
pressure
Using the ______ gear usually makes maintaining a balance between speed and pressure easiest
lowest
older PTO pumps were _____gpm, now some with full torque power take-offs that allow for ______gpm
500
1,250
horse power requirements for app must include accessories such as ________, ______ and vehicles ________
warning lights
air compressor
air conditioning
Front mount pumps are typically driven through a gear box and a clutch connected to a _____ to the front of the __________
drive shaft
crankshaft
on a front mounted pump, the ______ box has a step up gear ratio which causes the impeller of the pump to turn _____ than the engine.
gear
faster
typically a front mounted pump is rated at _______gpm
1,250 gpm
on front monted pump, the drive shaft must ALWAYS be matched to the _________ source
power
one disadvantage to front mounted pump is the possibility of the pump and gauges ________ in cold weather.this can be lessoned by the use of expernal lines that ciculate ______ fluid through the pump body.
freezing
radiator
During warm weather, front mounted pumps may restrict _______ to the engine.
air flow
Front mounted pumps are operate at the pump location. this is dangerous and a _____ must be provided to prevent the transmission from engaging.
lock
There should be a ______ light in the cab that flashes when front mounted pump is engaged.
warning
a front mounted pump may be _______ if driven while pump is running or with no ____ in pump.
damaged
water
a pump mounted laterally across the frame behind the engine and transmission is a ________ pump
Midship pump.
Power to a midship pump is supplied to the pump through the use of a split shaft gear case (transfer case) located in the ______ line between the transmission and the _____axle.
drive
rear
on a midship pump power can be diverted from the _______ and transmitted to the pump.
rear axle
midship pumps are driven by either a series of ______ or a ______chain or _______
gears
drive chain
on a midship pump, the impeller spins _____ or _____ times faster than the engine.
1 1/2 - 2 1/2
with the engine idling and the pump engaged, most speedometers will read _____ to _____mph. Some speedometers may read _____mph including PTO pumps with pumps engaged
10-15 mph
0mph
most Apps have a light on in the cab to show when the pump is ______
engaged
A D/O should not rely solely on the pump light. Other indications include
1.
2.
speedometer
hearing it engage
on automatic transmissions, it is possible for the ______ to be momentarily be engaged
transmission
If trying to go into pump and the gear shifter is shifted our of nuetral before being in pump, the engine may _____
stall
_________ pumps are used for asuliliary systesm including CAFS and gerators on Apps.
hydrostatic
Apps with rear mount pumps are becoming _________. These provide a more even weight on the _______ and offer more _______ space.
increasingly popular
chassis
compartment
a negative to rear mount pumps is that the D/O is exposed to _______. This can be alleaviated by placing the pump at one ________side
traffic
rear
Depneding on manufacturer, rear mount pumps may be powered by either a _______ or _______
split shaft tranny or a PTO
The primary piping system on a pump are :
1.
2.
3.
4.
intake
discharge
pump drains
pump valves
NFPA 1901 required all piping to be ______ resistant
corossion
Most pump piping is made of ____, ______, ________ or __________ and some rubber hoses
cast iron, brass, stainless steel or galvanized steel
piping system of fire pump much be capable of withstanding hydrostatic tests of _____psi before going in service
500 psi
in order to minimize friction loss, all APP piping and hoses must be designed to run as _____ as possible with minimum number of ______.
straight
bends
Water may enter the pump from either the ______ or ________
tank or external water supply
Accoring to NFPA 1901, pumpers with capacity 500gpm or less should have piping capable of flowing ______gpm. Those with capacity greater than 500gpm should be able to flow at least ______gpm
500 gpm
500 gpm
Many tank to pump piping is ____ inches in diameter
4 inches
moblie water supply units may feature ______ tank to pump lines
multiple
a leak in the tank to pump valve will not allow the pump to be _____ if the tank is empty.
primed
A ________ is tapped into the pump at a high point on the suction side or the impeller eye and use a priming valve. because of this, all intake lines in a centrifugal pump are normally ______ the eye of the impeller.
primer
below
A minimum of ___inch piping, valves and elbows must be used to supply 1.5, 13/4 and 2 inch handlines
2 inch
A pump with a 750gpm capacity must have at least _________ discharges. Pump less than 750gpm capacity need only one ______
two 2 1/2 inch discharges
2 1/2 inch discharge
discharges are usually equipped with a locking _________
ball valve
all valves should be designed and maintained so they are easily operated at preassures of up to ______psi
250
A tank fill line or tank recirculating valve allows to replenish the water tank when hooked up to an external ______
source
Apps with a water tank less than 1,000 gallons must have a fill line of at least ______inches in diameter
one inch
Tanks greater than 1000 gallons must have a fill line at least _____ inches in diameter
two inches
on a two stage pump, the fill line coming of the first stage may lead to ________ in the second stage
overheating
Some pumps have a booster line cooling valve or a ___________
bypass valve
An engine cooler circulates tank water through a heat exchanger to aid in ___________
cooling the engine
Valve life might be extended by _____ the pump of debris
flushing
most common type of valve is a ____ valve that permits the full flow of water through a line with minimul friction loss
ball
The most common two types of actuators for ball valves are
1.
2.
push/pull handles (t handles)
Quarter turn handles
A push pull valve usually has a flat handle that can be locked by turning it _____degrees
90 degrees
Quarter turn valve is open or closed by a _____degree movement of the handle
90
D/O must make sure intake valves are fully _____ or ______ by visual indicator on the pump panel
open or closed
______ or ______ valves are commonly used on large diameter intake and discharges
Gate or butterfly
Gate valves are opened by a _______ while butterfly valves operated by a _______
handwheel
quarter turn handle
NFPA 1901 requires that all intake or discharges are ____ inches or greater be equipped with slow acting valves.
3 inches
most pump connections are equipped with _____ valves on the line side of the control valve.
drain
after all air is removed through the bleeder valve it can be closed and the intake valve can be opened.
Drains must be supplied or located at the ______ point on the pump.
lowest
if master drain is opened up pressure or when vacuum is present the __ ring may be dmaged
O ring used as gasket for air tight
close all drains immediately after _____. Failing to will prevent successful drafting in future.
draining
A booster line may have to be _____ to drain properly. Some boosters are hooked up to the Apps _______ to blows it out.
pulled
air brakes
NFPA 1901 requires each app pumping system to have some type of ______ control device. It must operate in ____to_____ seconds after pressure rises and restricts the pressure from rising ___ psi above the set level
pressure
3-10 seconds
30 psi
the must be a _______ light in color to indicate that a pump has activated a reief valve to control pressure.
yellow
There are two basic concepts to pressure relief valves:
Those that relieve excess pressure on the _______ of the pump. And those that relieve pressure on the ______ side of the pump
discharge
intake
the most common form of a pressure relief valve is a ________
spring pilot valve
When pressure is too great the spring compresses sending water back into the ______
PUMP INTAKE
As hydraulic force is less than the force on the spring, the pilot valve will _______
stay closed
When the pump discharge pressure rises higher than allowed by the pilot valve setting, the ________ in the pilot valve ______
spring compresses
When the spring on the pilot valve compressed, the action allows the _______ valve to move to the ______ causing water to dump back into the _________
needle
left
pump intake
When the spring in the pilot valve stays closed and is not compressed, water stays in the main chamber and the main valve stays ______
closed
When the hydraulic force on the small end of the main valve is now greater than behind the main valve, the result is that the main valve ____ and permits part of the water to return to the ______side reducing ________pressure
opens
intake
discharge
A discharge pressure relief valve when activated takes pressure/water from the discharge side and dumps it back into the ______side
intake
Intake pressure relief valves are intended to protect pumps and hose from ____________
water hammer
Discharge pressure relief valves are ______ to react but are _______ to reset
quick
slower
Two basic type if intake relief valves:
1. one that is supplied by the manufacturer and is part of the pump manifold
2.
- is an add on device screwed onto the pump intake section
it is generally recommended that intake relief valves be set at ____psi above necessary operating pressure.
10 psi
most screw on intake valves are equipped with ____ that allow water supply to be stopped if preferred.
manual shutoff valves
you will also find ______ attached to intake pressure relief valves to remove excess air in LDH.
bleeder valve
________ is a pressure control device that controls the engine speed eliminating hazards from excess pressure.
pressure governor
Pressure in a pump can be controlled by one of two governors:
1.
2.
mechanical
electrical
A pressure governor works by controlling______
the engine speed by reducing it
Excess pressure is usually the result of ________
a hand line being shut down.
When excess pressure is built up, a tube in the discharge side of the pump tranmits the resulting pressure to a ________ device
governing
A pressure governor may be used in conjunction with the ______ control
throttle
Pressure governors: When drafting water returns to the _______ side of the pump. When pumping from a hydrant the water is discharged on the ______
intake
ground
Newer pumps are often equipped with ______ governors
electronic
electronic governors have pressure sensing elements that attach to the _______
discharge manifiold
an electronic governor controls pressure by adjusting the throttle by adjusting the amont of _____ supplied to the engine.
fuel
A pressure governor will control any pressure set above the set pressure and return the engine to ______ when it drops below that point.
idle
eletronic governors have a _______ feature that returns engine to idle if intake pressure drops below _____psi
cavitation
30 psi
pressure governors are _____ to respond and eliminate the need for a discharge _______ valve
quick
pressure relief
Another advantage to a electronic governor is that a when a discharge line is closed the engine RPM is adjusted, but the same ______ pressure is maintained on any lines still flowing. A mechanical governor would result in lower discharge pressure to _____ lines
discharge
all
D/Os must be familiar with different cut in/_______ ranges. If discharge pressure is reduced for a specific period of time, the governor will return to ______
cut out
idle
The ability to sucessfully draft is the ability to create a _____ pressure within the pump and intake hose than exist in the atmosphere.
lower
There are 4 types of primers:
1. positive displacement
2.
3.
4.
- Positve displacement
- exhaust
- vacuum
- air primers
most moern pumps use ______ primers
positive displacement primers
rotary vein primers are often powered by an _______ motor. this allows them to be operated regardless of engine speed.
electrical
primer oil helps to fill voids in gaps and fill iregularities in the housing.
Because the oil resivor on a priming pump is often pounted higher, than the pump itself, a vent hole is provided to break the _____ action as the tank drains
siphon
The general range for priming is _______ to _____ rpm
1000-1250 rpm
Most new Apps are slso equipped with _____less primers.
oil
exhaust primers are found on _______mounted pumps or _____ apps.
skid mounted pumps or older app
Exhaust primers use the same concept as a ____ eductor
foam
A vacuum primer is a simple device that makes use of the vacuuum already present in the ______ manifold or any gasoline driven engine
intake manifold
A vacuum primer works best near _____speed or _____ rpms
idle
low
Air primers use the ______ effect to create prime and has no moving parts or lubrications
venturi
A transmission temp gauge is also recommended for installation on the pump panel to monitor and ensure there is no damage to the ______
Tranny
The master _____ and ____ gauges are the two primary gauges used by the D/O to determine water pressure entering and leaving the pump.
master intake master discharge
The master intake gauge measures positive pressure or _______
vacuum under 0 on the gauge
The master intake valve is calibrated to ____to____psi of positive pressure and from ____to____ inches of mercury (vacuum) on the negative side.
0-600psi positive
0-30 inches
When a vacuum reading approaches ____inches the pump is nearing its capacity and is not able to supply additional lines.
20 inches
The tachometer displays engine speed in ________
RPM
The pumping engine coolant temperature indicator displays the temp of the _____ in the engine that powers the fire pump.
coolant
Pumping engine oil pressure indicator shows if adequate supply of oil is being delivered to the critical areas of the _____ during pumping.
engine
Pump overheat indicator is a audible or ______ indicator that warns D/O of an overheated pump.
visual
Voltmeter is a device used for measuring ______ voltage in an electrical system. Voltmeter also gives indication of the _____ condition.
existing
battery
Ammeter is a gauge that indicates both the ammount of electrical current being drawn from and provided to the vehicle’s _______
It also indicate the status of the vehicles alternator and charging system.
battery
Pump pressure indicators commonly called ______ may be connected to individual discharge outlets of the fire pump. the gauge must be on the outlet side of the ______ valve
discharge gauges
discharge
The engine throttle at the pump panel allow for increase or decrease of the engine speed which allow to D/O to control the amount of _____ that the pump supplies the discharge
pressure
an engine throttle knob is also called a _______
vernier
Primer controls on pump panel are usually _______, _______ or _____ lever
push button, toggle switch or pull lever
D/O should confirm the accuracy of a water display indicator light by inspecting the ______ opening to verify the tank is full.
fill
The primary function of an auxiliary cooling system is to control the temp of the ______ in the apparatus engine during pumping operations
coolant
Older apps have one of two different coolers: either the ______ or the _______
marine
or Immersion type
The marine cooler has a number of small _____. the cooler water from the pump contacts these tubes and cools the coolant inside them.
tubes
The immersion cooler the tubes or coils for the pump water are immersed in a container of coolant.
both types of auxiliary coolers are designed so coolant does ____ mix with the water.
NOT
Older Apps have a radiator fill valve that allows water from the pump to circulate in the radiator. This is an emergency use system only.
And finally, in extreme situations where an engine needs to be cooled while supplying hoselines, a ____ stream can be directed at the engine to maintain some cooling while interior crews withdraw.
water
